Rational Audiophile Loudspeaker System

[Einric]

The midrange in a 3-Way gets a bit of bandpass gain.
1-2db is common, you may need to pad the tweeter 3db or so.

 

[danvprod]

Thoughts on the following?

I have been considering the Firebox for the Audio Interface. It has 6 output and can be had on the used market for about $60. It still has my audio input for my turntable. The amplifier I have is a Pioneer VSX-D912, which sounds AMAZING for the price. Currently speakers are still planned as mentioned before.

Need to find a nice used laptop (with no fan) from CL.

 

[Pano]

FWW, I've used that Peerless 12 as well as GRS 15s on open baffle. Even 2x15" per side. Both are quite good woofers. I have not tried the GRS 12"
Have used them with various mid/tweeters with good results. The Vifa 3.5" or 4" fullrange drivers seem to mate well with these woofers. Search this forum for the Manzanita speaker project.

Although I have used active DSP crossovers of various flavors with these drivers, a simple 5 or 6 component passive crossover can be very satisfactory. Sometimes you just don't need the complexity, as fun as it may be to fiddle with.

 

[danvprod]

Thanks, Pano. I've read both threads (on AC and DIY) about the Manzanita project. It is interesting -- I may look into that Vifa as an option. As I recall, in Manzanita, the crossover is higher -- like 700 Hz or so?

Another midwoofer that I have been considering is the one that SL uses in the LX Mini and LX 521: https://www.madisoundspeakerstore.com/approx-4-fullrange/seas-prestige-fu10rb-h1600-04-4-full-range/

I've also considered for the HF the new Dayton AMT, similar to the configuration that is used in the Hestia V (on AC): New Build: The Hestia V

That might work well.

 

[JohnR]

I've used the Firebox as a 6-channel DAC with Pure Music (mac) and although it was a while ago my recollection is that it worked fine. Just be careful not to create a feedback loop if using it for measurements as well. (I did have that issue but don't remember what the specific cause was.)

 

[JohnR]

BTW I'm not sure that the analog input in your diagram will work, it's not going through the crossover.

 

[danvprod]

BTW I'm not sure that the analog input in your diagram will work, it's not going through the crossover.

I suppose you are right -- I think in the DSP software, I can choose between a local stream and an input on the sound card. So it would require me turning off the direct monitoring, and running the input through the DSP software, and back out the 6-channels into the amp and into the speakers.

I'll have to look at a number of options for multi-channel DACs. The easiest, would be a USB sound card that has ASIO support. I think something like this would also do the trick: (http://www.amazon.com/gp/product/B00K85XT8W/ref=ox_sc_sfl_title_5?ie=UTF8&psc=1&smid=ATVPDKIKX0DER)

 

[Juhazi]

Is a minidsp 2x8 or 4x10HD a too easy way? I heartily recommend the 4x10HD, very versatile and many input/output options!
miniDSP 4x10 Hd | MiniDSP

 

[danvprod]

I've thought about the MiniDSP 4x10 HD. In fact, I use the 2x4 right now. The 4x10 HD does not have any FIR-filter capabilities right now, so I would also have to get a OpenDRC-DI. I could go OpenDRC-DI via optical -> MiniDSP 4x10 HD (optical in) -> multi-channel amplifier. That's about a $800 proposition.

 

[danvprod]

The other option is to just build a LXMini and keep my MiniDSP 2x4

 

[danvprod]

In looking around for other designs, this seems to be a pretty "rational" design too.
https://www.madisoundspeakerstore.c...o-sb12.3-sb-acoustics-12-dual-midrange-3-way/

This design is definitely do-able in my two-box arrangement.

 

[sreten]

In looking around for other designs, this seems to be a pretty "rational" design too.
https://www.madisoundspeakerstore.c...o-sb12.3-sb-acoustics-12-dual-midrange-3-way/

This design is definitely do-able in my two-box arrangement.

Hi,

Not really, you don't have enough bass box volume.
And the carefully optimised x/o won't work as well as
intended with narrow separate mid/treble cabinets.

rgds, sreten.

 

[danvprod]

You make a good point @sreten. I wouldn't be going passive, so the crossover is less of an issue. I am more interested in the drivers. The woofer is obviously in a bigger cabinet (3.75 cu ft.) so that won't work.

I like this guy's system as well: 2channelaudio: 2CA 12.5.1 | Active DSP 12 Inch 3 Way Build

He uses the SB29RDC-C000-4 for a tweeter: https://www.madisoundspeakerstore.c...b-acoustics-sb29rdc-c000-4-ring-dome-tweeter/

And SEAS 5.5" midrange: https://www.madisoundspeakerstore.c...ige-mca15rcy-h1262-5.5-coated-paper-midrange/

This is the model with the SB and the SEAS, seems to be a really nice integration between them -- this would be running the seas from 275-3kHz and running the SB above that.

I've been looking and modeling the woofer cabinet with the Dayton DC300-8, which would give ma a F3 of 42 Hz in a 2.0 cu ft box with a Q of .73.
Dayton Audio DC300-8 12" Classic Woofer

Maybe a better option than the Peerless?

Also, since I am doing this in DSP, I could also consider a Linkwitz transform for the 12"

This option would be:
41.41 for each woofer, 54.25 for each tweeter, and 81.50 for each midrange. Total driver cost is: ~ $355

 

[natehansen66]

The Allocator is a VST plugin.

I'm curious why you think JRiver is more powerful than the Allocator. I understand they are really two different tools -- I still have a decision to make about where to house my music library/streaming services.

IIRC for the way I use it MC is more flexible and you pretty much have no limits on how many filters you can use. The convolver is nice as well. I figured with Allocator I would need a vst host so it's nice to do everything with one piece of sw. Keeps it simple. You would need external sw for phase correction such as rePhase.

The UI on Allocator wins over MC's dsp tho.

 

[benb]

Considering the following for drivers:
...
5" Dayton Reference woofer for the midrange driver(175Hz-2000Hz):
Dayton Audio RS125P-4 5" Reference Paper Woofer 4 Ohm
...
Total driver cost is $372. I'm a bit concerned about the low sensitivity of the midrange. Maybe I will keep looking.

I'm wondering what worries you about driver sensitivity in an active system. Worse case, you might need a higher power amp to drive the midranges to as loud as you want. Is there something else I'm missing here?

Also, I was reading this thread yesterday, and the last post (#6) leads to the "Rational" author's Wordpress blog, specifically the post on his speaker design (think of it as a more long-winded version of the article in the OP), as well as other posts on other hifi-related things:

https://therationalaudiophile.wordpress.com/2014/08/10/what-price-the-truly-rational-audio-system/

 

[5th element]

The Peerless SLS are an excellent budget choice because they contain shorting rings which most around that price point do not. This helps to lower distortion.

The Dayton Reference series of drivers represent excellent value for money also and the RS125P would be a very good choice for a midrange, as would the RS125. The RS28F is also an excellent tweeter and will allow you a lot of flexibility with the crossover.

 

[phase_accurate]

I'm wondering what worries you about driver sensitivity in an active system. Worse case, you might need a higher power amp to drive the midranges to as loud as you want. Is there something else I'm missing here?

The thermal power compression behaviour can be quite different for the midrange, leading to a recessed midrange after some loud listening.

Regards

Charles

 

[danvprod]

My thought with trying to match the efficiencies was that I have a 6-channel amplifier that I am going to be powering the speakers with -- I don't want to have to pad down the woofer and tweeter more than I have to and running out of headroom. That was my general thought.

Also, anyone have any experience with the EV DC One loudspeaker processor?
Electro-Voice DC-One 2-in/6-out sound system processor

No FIR filters in this, but does have 6 outputs, PC-based configuration utility and AES/EBU in (which I could manage using something like this): Hosa CDL 313 SP dif Coax to AES EBU Digital Audio Interface | eBay

Just a thought.

 

[classdpwr]

I used an old MacBook Air and an HDMI cable. That's it. The multi-channel software is native to OSX. I'm not sure if there's much in the way of caveats. And now I can design any speakers I want in the future. Sweet

https://www.youtube.com/watch?v=YsFoWK2IWn4

 

[danvprod]

Thanks, @classdpwr. We've conversed on the Rational Audiophile's blog. I do rather like your approach. Using the older MacBook Air is a solid idea as well. And not being tied to a single piece of hardware is very good as well. HDMI Audio is very novel and simple to get the multi-channel audio out of your computer without a multi-channel DAC etc.

Your AVR simplifies the process greatly -- it affords, multi-channel application, multi-channel DACs, multi-channel volume control into a single, inexpensive unit.